Re: Is gp_exit() used at exit in current gnuplot?

[Tatsuro M. <tma...@ya...>]

----- Original Message -----

> From: Tatsuro MATSUOKA 
> To: gnu...@li...
> Cc: 
> Date: 2017/2/28, Tue 10:38
> Subject: Is gp_exit() used at exit in current gnuplot?
> 
>T his is related to bug #1913.
> 
> In stdfn.c
> 
> there stated
> 
> 
> /* Calls the cleanup functions registered using gp_atexit().
>  * Normally gnuplot should be exited using gp_exit(). In some cases, this is not
>  * possible (notably when returning from main(), where some compilers get
>  * confused because they expect a return statement at the very end. In that
>  * case, gp_exit_cleanup() should be called before the return statement.
>  */
> 
> 
> *****************************
> 
> Normally gnuplot should be exited using gp_exit().
> ***************************
> 
> 
> However, quick test by gdb
> 
> gdb gnuplot
> b gp_exit_cleanup
> b gp_exit
> b debug_exit_handler
> r
> 
> At gnuplot prompt
> 
> gnuplot> exit
> 
> gdb tells that gnuplot does not end by gp_exit but by debug_exit_handler.
> by exit command value of exit_handlers
> 
> 
> On  cygwin
> 
> Breakpoint 1, gp_exit_cleanup () at ../../gnuplot/src/stdfn.c:440
> 440     {
> (gdb) n
> [New Thread 8120.0x26b8]
> 447         while (exit_handlers) {
> (gdb) n
> 449             (*handler->function)();
> (gdb) n
> [New Thread 8120.0x27cc]
> 451             exit_handlers = handler->next;
> (gdb) n
> 452             free(handler);
> (gdb) n
> 451             exit_handlers = handler->next;
> (gdb) n
> 452             free(handler);
> (gdb) n
> 447         while (exit_handlers) {
> (gdb) n
> 449             (*handler->function)();
> (gdb) n
> 451             exit_handlers = handler->next;
> (gdb) n
> 452             free(handler);
> (gdb) n
> 451             exit_handlers = handler->next;
> (gdb) n
> 452             free(handler);
> (gdb) n
> 447         while (exit_handlers) {
> (gdb) n
> 454     }
> (gdb) n
> main (argc=<optimized out>, argv=<optimized out>)
>     at ../../gnuplot/src/plot.c:694
> 694         return exit_status;
> (gdb) n
> 695     }
> (gdb) n
> 0x61007acf in cygwin_exit_return () from /usr/bin/cygwin1.dll
> (gdb) c
> Continuing.
> 
> Breakpoint 3, debug_exit_handler () at ../../gnuplot/src/stdfn.c:461
> 461         if (exit_handlers) {
> (gdb) p exit_handlers
> $1 = (struct EXIT_HANDLER *) 0x0
> (gdb) c
> Continuing.
> [Thread 8120.0x1708 exited with code 0]
> [Thread 8120.0x26b8 exited with code 0]
> [Thread 8120.0x1094 exited with code 0]
> [Thread 8120.0x27cc exited with code 0]
> [Thread 8120.0x22c8 exited with code 0]
> [Inferior 1 (process 8120) exited normally]
> 
> 
> The above also happens on lubuntu.
> 
> Similar behavior is observed on windows
> 
> 
> Entering exit command 
> gp_exit_cleanup () is called in main in plot.c on Cygwin and lubuntu. 
> gp_exit_cleanup () is called in WinMain (wgnuplot) or main (gnuplot) in 
> wimmain.c on windows. 
> 
> 
> Even exit command, gp_exit() seems not to be used.
> 
> Is 
> 
> *****************************
> 
> Normally gnuplot should be exited using gp_exit().
> ***************************
> 
> true at present ?
> 
> Tatsuro
> 

Excuse me for my writing without reading the code in detail.
gp_exit() seems to be used in many place in the code.
Therefore gp_exit() is surely used in current gnuplot.
However, "gnuplot> exit" does not use gp_exit() as written in the previous post.

I feel that the message
 
Gnuplot not exited using gp_exit(). Exit handlers may not work correctly!

in debug_exit_handler in stdfn.c is better to be modified.

Tatsuro